I'm looking for a dataset containing settlement boundaries for United Kingdoms.
In short example I'm looking for a dataset that would allow me to draw something like the following (orange line):
Settlement boundaries are defined by local authorities (or national park authorities, within national parks) as part of the processing of granting permission for new or adapted buildings. However, the process used to define them varies in different areas and not all settlements will have a defined boundary, so you should not trust that they are consistent across areas.
There doesn't appear to be a national dataset of settlement boundaries, probably because central government does not need the information so would not benefit from collecting it from local authorities. Some local authorities have released settlement boundaries on data.gov.uk but they are often in different formats and not all are available for download.